Carbonite

Carbonite was a liquid substance that was made from carbon gas and could change into a solid through rapid freezing. Goods could be encased in carbonite for preservation, through a process known as carbon-freezing.[1]
Carbonite blocks could also be used to place people in hibernation.[2] Before the invention of the hyperdrive, some early spacers would use carbonite to endure long voyages. That technique, however, had brutal side effects, collectively referred to as hibernation sickness.[3] Droids such as the DLC-13 mining droid could be made out of heat-resistant carbonite.[4]